All the 7 media servers are with the same platform, each media server has 3 HBAs for FT services, and each HBA connected with 6-12 clients. Each client has 2-3 policy, and jobs run at the same time may reach up to 15 per media server. I noticed that during one backup period, 12 jobs are started in that media, only 3 successful started, others failed with status 83, the Devices-Media Servers-View FT Conncetions shows only 3 connections.

It's strange that the error occurs in random client, even one job failed with status 83, after an hour another job in the same client works fine.

Some configurations are as follows:

NetBackup Version: 7.1

OS(both media adn client): SUSE Linux Enterprise Server 10 (x86_64)

Storage Unit: VTL with 8 drivers, maximum streams per drive is set to 4